A nude protester faces off against Federal law enforcement officers, deployed under the Trump administration's new executive order to protect federal monuments and buildings, during a protest against racial inequality in Portland, Oregon, U.S. July 18, 2020. (Photo by Nathan Howard/Reuters)

A member of the Eton public school O.T.C. (Officers Training Corps) practising shouting out orders during a training session, 20th January 1940. (Photo by Hulton Archive/Getty Images)

Fort Bourtange is a star fort located in the village of Bourtange, Groningen, Netherlands. It was built in 1593 under the orders of William the Silent. Its original purpose was to control the only road between Germany and the city of Groningen, which was controlled by the Spaniards during the time of the Eighty Years' War.

Residents observe a police officer take up position during an operation at the Mare slums complex in Rio de Janeiro March 25, 2014. The federal troops have taken control of security operations in Mare slums complex to help quell a surge in violent crime following attacks by drug traffickers on police posts in three slums on the north side of the city, government officials said. (Photo by Ricardo Moraes/Reuters)

Residents protest a police operation targeting drug traffickers in the Jacarezinho favela of Rio de Janeiro, Brazil, Thursday, May 6, 2021. At least 25 people died during the operation, including one police officer and 24 suspects, according to the press office of Rio's civil police. (Photo by Silvia Izquierdo/AP Photo)

A zoo curator using a kayak tries to catch a pelican in order to move him into its winter enclosure at the zoo in Liberec, Czech Republic, Tuesday, November 16, 2021. (Photo by Petr David Josek/AP Photo)

Children playing on Walled City rooftop in Hong Kong, 1989. The lack of formal governance in the Walled City led to challenges, but it also fostered a unique system of informal social order. (Photo by Greg Girard/The Guardian)

Military policemen take part in an operation at Cidade de Deus favela in Rio de Janeiro, Brazil, on February 01, 2018. (Photo by Mauro Pimentel/AFP Photo)